 /*******************************************************************************
  * Copyright (c) 2000, 2005 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.ui.commands;

 import java.util.List ;
 import java.util.Map ;

 /**
  * <p>
  * An instance of <code>ICommand</code> is a handle representing a command as
  * defined by the extension point <code>org.eclipse.ui.commands</code>. The
  * identifier of the handle is identifier of the command being represented.
  * </p>
  * <p>
  * An instance of <code>ICommand</code> can be obtained from an instance of
  * <code>ICommandManager</code> for any identifier, whether or not a command
  * with that identifier defined in the plugin registry.
  * </p>
  * <p>
  * The handle-based nature of this API allows it to work well with runtime
  * plugin activation and deactivation. If a command is defined, that means that
  * its corresponding plug-in is active. If the plug-in is then deactivated, the
  * command will still exist but it will be undefined. An attempts to use an
  * undefined command will result in a <code>NotDefinedException</code> being
  * thrown.
  * </p>
  * <p>
  * This interface is not intended to be extended or implemented by clients.
  * </p>
  *
  * @since 3.0
  * @see ICommandListener
  * @see ICommandManager
  * @see org.eclipse.core.commands.Command
  * @deprecated Please use the "org.eclipse.core.commands" plug-in instead.
  */
 public interface ICommand extends Comparable {

     /**
      * Registers an instance of <code>ICommandListener</code> to listen for
      * changes to attributes of this instance.
      *
      * @param commandListener
      * the instance of <code>ICommandListener</code> to register.
      * Must not be <code>null</code>. If an attempt is made to
      * register an instance of <code>ICommandListener</code> which
      * is already registered with this instance, no operation is
      * performed.
      */
     void addCommandListener(ICommandListener commandListener);

     /**
      * Executes with the map of parameter values by name.
      *
      * @param parameterValuesByName
      * the map of parameter values by name. Reserved for future use,
      * must be <code>null</code>.
      * @return the result of the execution. Reserved for future use, must be
      * <code>null</code>.
      * @throws ExecutionException
      * if an exception occurred during execution.
      * @throws NotHandledException
      * if this is not handled.
      */
     Object execute(Map parameterValuesByName) throws ExecutionException,
             NotHandledException;

     /**
      * Returns the map of attribute values by name.
      * <p>
      * Notification is sent to all registered listeners if this property
      * changes.
      * </p>
      *
      * @return the map of attribute values by name. This map may be empty, but
      * is guaranteed not to be <code>null</code>. If this map is not
      * empty, its collection of keys is guaranteed to only contain
      * instances of <code>String</code>.
      * @throws NotHandledException
      * if this is not handled.
      */
     Map getAttributeValuesByName() throws NotHandledException;

     /**
      * <p>
      * Returns the identifier of the category of the command represented by this
      * handle.
      * </p>
      * <p>
      * Notification is sent to all registered listeners if this attribute
      * changes.
      * </p>
      *
      * @return the identifier of the category of the command represented by this
      * handle. May be <code>null</code>.
      * @throws NotDefinedException
      * if the command represented by this handle is not defined.
      */
     String getCategoryId() throws NotDefinedException;

     /**
      * <p>
      * Returns the description of the command represented by this handle,
      * suitable for display to the user.
      * </p>
      * <p>
      * Notification is sent to all registered listeners if this attribute
      * changes.
      * </p>
      *
      * @return the description of the command represented by this handle.
      * Guaranteed not to be <code>null</code>.
      * @throws NotDefinedException
      * if the command represented by this handle is not defined.
      */
     String getDescription() throws NotDefinedException;

     /**
      * Returns the identifier of this handle.
      *
      * @return the identifier of this handle. Guaranteed not to be
      * <code>null</code>.
      */
     String getId();

     /**
      * <p>
      * Returns the list of key sequence bindings for this handle. This method
      * will return all key sequence bindings for this handle's identifier,
      * whether or not the command represented by this handle is defined.
      * </p>
      * <p>
      * Notification is sent to all registered listeners if this attribute
      * changes.
      * </p>
      *
      * @return the list of key sequence bindings. This list may be empty, but is
      * guaranteed not to be <code>null</code>. If this list is not
      * empty, it is guaranteed to only contain instances of
      * <code>IKeySequenceBinding</code>.
      */
     List getKeySequenceBindings();

     /**
      * <p>
      * Returns the name of the command represented by this handle, suitable for
      * display to the user.
      * </p>
      * <p>
      * Notification is sent to all registered listeners if this attribute
      * changes.
      * </p>
      *
      * @return the name of the command represented by this handle. Guaranteed
      * not to be <code>null</code>.
      * @throws NotDefinedException
      * if the command represented by this handle is not defined.
      */
     String getName() throws NotDefinedException;

     /**
      * <p>
      * Returns whether or not the command represented by this handle is defined.
      * </p>
      * <p>
      * Notification is sent to all registered listeners if this attribute
      * changes.
      * </p>
      *
      * @return <code>true</code>, iff the command represented by this handle
      * is defined.
      */
     boolean isDefined();

     /**
      * <p>
      * Returns whether or not this command is handled. A command is handled if
      * it currently has an <code>IHandler</code> instance associated with it.
      * A command needs a handler to carry out the {@link ICommand#execute(Map)}
      * method.
      * </p>
      * <p>
      * Notification is sent to all registered listeners if this attribute
      * changes.
      * </p>
      *
      * @return <code>true</code>, iff this command is enabled.
      */
     boolean isHandled();

     /**
      * Unregisters an instance of <code>ICommandListener</code> listening for
      * changes to attributes of this instance.
      *
      * @param commandListener
      * the instance of <code>ICommandListener</code> to unregister.
      * Must not be <code>null</code>. If an attempt is made to
      * unregister an instance of <code>ICommandListener</code>
      * which is not already registered with this instance, no
      * operation is performed.
      */
     void removeCommandListener(ICommandListener commandListener);
 }

